Method of repairing broken metallic structures by welding



refentea .my 13,1926.'

UNITED- STATES;g iuvr'rsirrf'1 OFFICE.

BOYAL-IATIICE, 0F PmADELPHIA,

miren or mamme miem mauro srnucrunns BY wnnnnre.

ippneetion mea september 1s, i924. serial This invention relates to a method of reairing cracked, fractured or liroken metal- 1c structures by welding.

Heretofore cracked, fractured or broken structures have been repaired by forming a mechanical patch bolts, cap screws or the like being emplo ed, but this method presents many. disadyvantages in that an oper- `.at0r or repair man oftentimes twisted the heads off of cap screws, stripped the bolt threads or broke the bolt, and-sometimesthe bolt would haveia .loose t resulting intwisting thereof and precluding the tightening of the patch. y Q i Further, it has beenfound that frequently insuicient space prohibited the use of bolts, caps screws or the like.

`Itis therefore one object of this invention to overcome the before mentioned disadvantage.

It is a further object of this invention to obtain a shrink lit in ythe repairing of cracked, fractured or broken metallic struc= tures.

It is a still further Yobject of this invention to secure a strocoint between plates A,

or sheets in a quick ient manner, whereby to ,repair cracked, fractured or broken' metallic structures. Y Another object of this invention` is to pro-V` vide a method of welding together plates or other metallic articles whereby to repair ythe same.

The invention is illustrated by way of ex- Y a stationary engine showing a modification of the invention, and

Figs. 6k and -7 are sectional views on the line 4-4 of Fig. 5 showing succeive steps in the method of the modification shown in 5. v Fjleferring more particularly to the drawings, in whichsimilar characters of referf sink exten Vter of 'an inc less than the thickness of we HEISSUQ ence designate similar parts in the sever views, A designates a piece of metal of any structure which has had a portion thereof broken, the sections being designated as 1 and 2, while 3 indicates the line ofbreak, which in the instance shown is of irregular contour. l.

As therst 'stepr in my method ,of repairing the broken structure, provided the' sections 1 and 2 are complementary, I first drill or otherwise formed a number of openings'4 in section 2, which openings are then countersunk as shown' at 5; each counterto a depth about one quarsection 2 at the place be' drilled. This depth hasbeen found satisactory in practice but, of course, the depth of the. countersink may vary lin accordancewith the particular job, and I do not limit this 'inviligion to any specific depth of counters f When the` openings 4 have been countersunk, the ,section 2 is placed'in position against section 1, and held thereagainst `in any suitablel manner, whereupon 'openings' 6 I,are drilled in section 1, which openings are aligned, naturally, with-openings 4:; section 2 serving as a template or masterplate.

The ,openings are then tapped or threaded as'shown at 7, the template removed if neceary, and then thread 8 are secured within said openings, seeFig. 3.

The dra osethe studs 8 assecured within te' openings by being ed therein;y the studs thus being held withthread-y in the openings in a mechanical manner.- I

Thev studs are secured directly to the plate -1 in a mechanical manner in contradistinction to an arrangement whereby lthe studs may be held to or within a plate by added means, such for example as the means shown in the British patent to The Quasi-Arc CompanyNo. 114,268, of 1918, in which patent the studs are secured to the plate by means of welding material, the studs .thus indirectly secured to the plate. By the use of the word mechanically I do not infer or mean that the studs are placed in pci sit-ion by mechanical apparatus, such for example, a welding machine, but I mean that the studs 'in their secured position in the plate are retained mechanically i'n such -se f cured position.

In practice it has been found-.advisable tio provide studs of such length that they extend into section 2 at least one uarter of tric Welding, for the reason that electric an inch beyond the lowest line di counter- Welding may be accurately controlled and sink. It has been found in practice also,

i that ductile studs are highly satisfactory but welds to finish off the exterior surface.

obviously. substantially non-ductile studs may be used within the spirit and scope of the invention.

Plates 1 and 2 being in the position shown in Fig. 2 with studs 8 in place, I now Weld the studs 8 to plate or section 2, and the welding is continued until the entire countersink is filled as shown in Figp/l at 9. It will be noted that in reality a head 9 has been formed on stud 8, the head becoming an integral part of section 2 and stud 8. Y

Inasmuch as section 2 and stud 8 are both heated during the welding, upon cooling.

.section 2 contracts and a shrink lit thereof to section 1 is obtained.

Following the welding. any surplus metal at the Weld may be removed in any suitable manner to finish off the surface adjacent the Weld, thus eliminating any protruding metal.

Referring now to Figs. 5, 6 and 7, the nu- `meral 10 designates a portion of a stationary engine which is cracked or fractured as shown at 11. It is impossible to remove one section from the other so I first seal the crackas shown at 12, preferably by removing metal adjacent the crack to form a V, and then Welding the V. y

It is not always necessary to seal the crackbut it has been found advisable under many conditions.

I then obtain a plate 13 of suitable/shape for the repair job, and drill therethrough a plurality of openings 14y which are countersunk as shown at 15 in a manner similar to those heretofore described.

Next. I take plate 13 and temporarily position it against the surface 10 and drill openings therein, which are aligned with the openings 14, plate 13 serving as a master plate. It has been found that by providing a plate 13 formed of ductile weldable material. highly satisfactory results are obtained but I do not limit myself to the use of a plate of this character as obviously, a non-ductile plate may be employed within the spirit and scope of the invention.

Studs 16 are secured in the openings in plate or surface 10, the studs extending into plate 13, as shown. The studs are then welded to plate 13 as described heretofore and any surplus metal removed from the It will be apparent that the plate 13 bridges the crack or fracture 11 and any stresses or strains to which the repaired vstructure may be subjected are transmitted to the brldging element or plate 13 by reason of its connection with the surface 10.

This invention has been practiced by eleca complete, nice, and durable repair effected. From the above, it is believed that the invention will be fully apparent'to those skilled in the art, but I desire it understood/ that various changes in form and proportions may be made without departing from the spirit of the invention.

ll'hat I claim as my invention and desire to secure by Letters Patent isz- 1. The method of joining metal plates or the like which comprises forming countersunk perforations in one of said pla-tes, mechanically securing studs to the other plate. said studs being aligned with the aforesaid perforations, superposing the perforated plate on the other plate with the studs of the latter extended into the perforations. and then welding the studs to the superposed plate to lill the countersinks whereby to form a welded head on each of said studs.

2. The method of repairing cracked or broken structures which comprises securing vstuds in said structure, said structure providing` vthe holding means for said studs, superposing a perforated plate on said struc ture to brid e the crack or break with the studs exten ing into the perforations. and finally Welding said studs tosaid perforated plate.

3. The method of repairing cracked or broken structures which comprises securing studs in said structure, said structure providing the holding means for said studs, superposing a perforated plate on said structure to bridge the crack or break with the studs extending into theperforations, and finally filling said perforations with Welding material to form a head on said studs to unite the superposed plate therewith.

4. The method of Welding together sections of broken metallic ructures which consists in forming countersunk perforations in one of the sections, forming tapped apertures in the other section, securing studs in said tapped apertures, superposing the perforated section on the other section with the studs positioned in said perforations, and finally electrically welding the portions of the studs Within the perforations to said perforated section in the countersunk perfortions to form a. head at the end of each stu 5. The method of repairing cracked metallic structures which consists in sealing the crack, forming a plurality of perforations in a plate, forming a plurality of recesses in the cracked structure which align with the perforations in said plate, securing studs directly to said cracked structure therein, the recees in said recesses corresponding in size with said studs whereby the latter are aligned with each other and with soV tions in a plate, forming a plurality of recesses in the cracked structure which align with the perforations in said plate, securing studs directly to the cracked structure therein the recesses in said recesses corresponding in size with the studs whereby the latter are aligned with each other and with the aforesaid perforations, superposing the f plate on the cracked structure wfith the studs extendin finally electrica ly plate.

7. The method'of repairing cracked meweldng the studs to said tallic structures which consists in sealing the crack, forming/a plurality of perforations in a plate, forming a plurality of recesses in the cracked structure which align with thek perforations in Vsaid plate, securing studs 1n the recesses in the cracked structure, said recesses being so formed as to align the studs rwith each other and with the aforesaid per- 'forations, superposing the plate on the into the perforations, andv in, ductile projecting members mechanicall 35 secured thereto on each side of said crac or break, and a substantially ductile plate welded to said project' members and bridging said crack or brea 9. A plate having a crack or break therein, projecting members mechanically secured in said plate on each side of said crackkor break, and a second plate arranged adjacent j said first named plate and welded to. said projecting members and bridging said crack or break to transmit strains to which said first named plate is subjected from the projecting members on one side of the crack or break to the. projecting members on the other side of the crack or break.

10. The method of joining vmetal plates or the like which comprises orming perforations in one of said plates, securing projectin studs in the other plate, said plate provi ing the holding means forsaid studs, whereby said studs are positively aligned with each other and with the perforations in said first mentioned plate, then superposing the perforated plate on said second named plate with the studs extending into the perforations therein, and lfinally welding the studs to the perforated plate to fill the countersid'nks and form a head on each of said stu s. l

ture.

ROYAL a MA'ITICE. 

